Short answer: When a deadbolt suddenly grinds, sticks, or won't throw all the way, most people blame the lock, but the real culprit is usually the door and frame shifting a fraction of an inch. Here is how a pro diagnoses the difference and fixes it for good.
When a deadbolt suddenly grinds, sticks, or won't throw all the way, most people blame the lock, but the real culprit is usually the door and frame shifting a fraction of an inch. Here is how a pro diagnoses the difference and fixes it for good.
The most common reason a deadbolt gets hard to throw is that the bolt no longer lines up with the hole in the strike plate; the door has settled on its hinges or the frame has moved with seasonal humidity, something Foster City's cool, damp bayside air can nudge as wood swells and shrinks, so the bolt scrapes the metal instead of sliding cleanly through. The second suspect is a dirty or dry cylinder, where years of dust and hardened old lubricant leave the pins sluggish and the key hard to turn even though nothing is actually broken. The third is a worn or poorly copied key whose cuts no longer match the pins, which feels like the lock catching and often comes right before a snapped key. Telling these apart is the whole job: a bolt that is tight only when the door is shut but smooth when it is open points to alignment, while stiffness even with the door open points to the cylinder or the key.
Start with the alignment test by throwing the deadbolt with the door standing wide open; if it slides freely, the lock is fine and the fix lives at the frame, not the cylinder. Look at the strike plate for a shiny scrape mark that shows exactly where the bolt is striking, and sometimes tightening loose hinge screws, or swapping one for a longer screw that bites into the framing behind the jamb, lifts a sagging door just enough to bring things back into line. For a cylinder that is stiff even with the door open, a puff of powdered graphite or a dry Teflon lock lubricant worked in with the key can restore smooth action, and again you should avoid WD-40 and any household or cooking oil, which attract grit and make it worse over time. What you should not do is force a bolt that refuses to throw fully, or leave the door unlocked to dodge the hassle, because a bolt that only goes halfway is not actually securing anything.
A pro confirms the diagnosis quickly and then corrects the geometry rather than fighting it, filing or repositioning the strike plate, adjusting the mortise, re-shimming or re-hanging a sagging door, and cleaning and re-lubricating or re-pinning the cylinder so the key turns like new. If the key was the problem, they cut a fresh one to the correct depths, and if the hardware is genuinely worn out they will tell you honestly whether a repair or a replacement lock is the better value instead of pushing a whole new set on you. A service call for a sticking-lock or alignment fix commonly falls in a typical range of about $75 to $150 for the visit and labor, with parts such as a new strike plate or deadbolt added only if needed. The payoff is a door that locks with one smooth motion, which is both more secure and far less likely to leave you with a key snapped off in the cylinder down the road.
The most common reason a deadbolt gets hard to throw is that the bolt no longer lines up with the hole in the strike plate; the door has settled on its hinges or the frame has moved with seasonal humidity, something Foster City's cool, damp bayside air can nudge as wood swells and shrinks, so the bolt scrapes the metal instead of sliding cleanly through. The second suspect is a dirty or dry cylinder, where years of dust and hardened old lubricant leave the pins sluggish and the key hard to turn even though nothing is actually broken. The third is a worn or poorly copied key whose cuts no longer match the pins, which feels like the lock catching and often comes right before a snapped key. Telling these apart is the whole job: a bolt that is tight only when the door is shut but smooth when it is open points to alignment, while stiffness even with the door open points to the cylinder or the key.
Start with the alignment test by throwing the deadbolt with the door standing wide open; if it slides freely, the lock is fine and the fix lives at the frame, not the cylinder. Look at the strike plate for a shiny scrape mark that shows exactly where the bolt is striking, and sometimes tightening loose hinge screws, or swapping one for a longer screw that bites into the framing behind the jamb, lifts a sagging door just enough to bring things back into line. For a cylinder that is stiff even with the door open, a puff of powdered graphite or a dry Teflon lock lubricant worked in with the key can restore smooth action, and again you should avoid WD-40 and any household or cooking oil, which attract grit and make it worse over time. What you should not do is force a bolt that refuses to throw fully, or leave the door unlocked to dodge the hassle, because a bolt that only goes halfway is not actually securing anything.
A pro confirms the diagnosis quickly and then corrects the geometry rather than fighting it, filing or repositioning the strike plate, adjusting the mortise, re-shimming or re-hanging a sagging door, and cleaning and re-lubricating or re-pinning the cylinder so the key turns like new. If the key was the problem, they cut a fresh one to the correct depths, and if the hardware is genuinely worn out they will tell you honestly whether a repair or a replacement lock is the better value instead of pushing a whole new set on you. A service call for a sticking-lock or alignment fix commonly falls in a typical range of about $75 to $150 for the visit and labor, with parts such as a new strike plate or deadbolt added only if needed. The payoff is a door that locks with one smooth motion, which is both more secure and far less likely to leave you with a key snapped off in the cylinder down the road.
Call (650) 376-0883 and describe the situation, your exact location, and what you need. Timing is confirmed on that call rather than promised in advance.
Call for help: (650) 376-0883 — a straight answer and an honest estimate before any work begins.